<template>
  <div class="course">
    <Header></Header>
    <div class="main">
      <!-- 筛选条件 -->
      <div class="condition">
        <ul class="cate-list">
          <li class="title">课程分类:</li>
          <li :class="filter.category===0?'this':''" @click="filter.category=0">全部</li>
          <li :class="filter.category===category.id?'this':''" v-for="category in category_list"
              @click="filter.category=category.id" :key="category.name">{{ category.name }}
          </li>
        </ul>

        <div class="ordering">
          <ul>
            <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选:</li>
            <li class="default" :class="(filter.ordering==='id' || filter.ordering==='-id')?'this':''"
                @click="filter.ordering='-id'">默认
            </li>
            <li class="hot" :class="(filter.ordering==='students' || filter.ordering==='-students')?'this':''"
                @click="filter.ordering=(filter.ordering==='-students'?'students':'-students')">人气
            </li>
            <li class="price"
                :class="filter.ordering==='price'?'price_up this':(filter.ordering==='-price'?'price_down this':'')"
                @click="filter.ordering=(filter.ordering==='-price'?'price':'-price')">价格
            </li>
          </ul>
          <p class="condition-result">共{{ course_total }}个课程</p>
        </div>

      </div>
      <!-- 课程列表 -->
      <div class="course-list">
        <div class="course-item" v-for="course in course_list" :key="course.name">
          <div class="course-image">
            <img :src="course.course_image" alt="">
          </div>
          <div class="course-info">
            <h3>
              <router-link :to="'/free/detail/'+course.id">{{ course.name }}</router-link>
              <span><img src="@/assets/img/avatar1.svg" alt="">{{ course.students }}人已加入学习</span></h3>
            <p class="teacher-info">
              {{ course.teacher.name }} {{ course.teacher.title }} {{ course.teacher.signature }}
              <span
                  v-if="course.sections>course.publish_sections">共{{
                  course.sections
                }}课时/已更新{{ course.publish_sections }}课时</span>
              <span v-else>共{{ course.sections }}课时/更新完成</span>
            </p>
            <ul class="section-list">
              <li v-for="(section, key) in course.section_list" :key="section.name"><span
                  class="section-title">0{{ key + 1 }}  |  {{ section.name }}</span>
                <span class="free" v-if="section.free_trail">免费</span></li>
            </ul>
            <div class="pay-box">
              <div v-if="course.discount_name">
                <span class="discount-type">{{ course.discount_name }}</span>
                <span class="discount-price">￥{{ course.discount_price }}元</span>
                <span class="original-price">原价：{{ course.price }}元</span>
              </div>
              <span v-else class="discount-price">￥{{ course.price }}元</span>
              <span class="buy-now" @click="buy_now(course)">立即购买</span>
            </div>
          </div>
        </div>
      </div>
      <!-- 分页 -->
      <div class="course_pagination block">
        <el-pagination
            @size-change="handleSizeChange"
            @current-change="handleCurrentChange"
            :current-page.sync="filter.latest_id"
            :page-sizes="[2, 3, 5, 10]"
            :page-size="filter.limit"
            layout="sizes, prev, pager, next"
            :total="course_total">
        </el-pagination>
      </div>
    </div>
    <Footer></Footer>
  </div>
</template>

<script>
import Header from "@/components/Header"
import Footer from "@/components/Footer"

export default {
  name: "FreeCourse",
  data() {
    return {
      category_list: [], // 课程分类列表
      course_list: [],   // 课程列表
      course_total: 0,   // 当前课程的总数量
      filter: {
        category: 0, // 当前用户选择的课程分类，刚进入页面默认为全部，值为0
        ordering: "-id",    // 数据的排序方式，默认值是-id，表示对于id进行降序排列
        limit: 2,       // 单页数据量
        latest_id: 3,
      }
    }
  },
  created() {
    this.get_category();
    this.get_course();
  },
  components: {
    Header,
    Footer,
  },
  watch: {
    "filter.category": function () {
      this.filter.latest_id = 3;
      this.get_course();
    },
    "filter.ordering": function () {
      this.get_course();
    },
    "filter.limit": function () {
      this.get_course();
    },
    "filter.latest_id": function () {
      this.get_course();
    }
  },
  methods: {
    handleSizeChange(val) {
      // 每页数据量发生变化时执行的方法
      this.filter.limit = val;
      this.filter.latest_id = this.filter.limit;
    },
    handleCurrentChange(val) {
      // 页码发生变化时执行的方法
      this.filter.latest_id = val + 1;
    },
    get_category() {
      // 获取课程分类信息
      this.$axios.get(`${this.$settings.base_url}/course/category/`).then(response => {
        this.category_list = response.data.data;
        // console.log('category_list', this.category_list);
      }).catch(() => {
        this.$message({
          message: "获取课程分类信息有误，请联系客服工作人员",
        })
      })
    },
    get_course() {
      // 排序
      let filters = {
        ordering: this.filter.ordering, // 排序
      };
      // 判决是否进行分类课程的展示
      if (this.filter.category > 0) {
        filters.category = this.filter.category;
      }

      // 设置单页数据量
      if (this.filter.limit > 0) {
        filters.limit = this.filter.limit;
      } else {
        filters.limit = 5;
      }

      // 设置当前页码
      if (this.filter.latest_id > 3) {
        filters.latest_id = this.filter.latest_id;
      } else {
        filters.latest_id = 3;
      }

      // 获取课程列表信息
      this.$axios.get(`${this.$settings.base_url}/course/`, {
        params: filters
      }).then(response => {
        this.course_list = response.data.data;
        // console.log('course_list', this.course_list);
        this.course_total = this.course_list.length;
        // console.log('course_total', this.course_total);
      }).catch(() => {
        this.$message({
          message: "获取课程信息有误，请联系客服工作人员"
        })
      })
    },
    buy_now(course) {
      let token = this.$cookies.get('token');
      if (!token) {
        this.$message({
          message: '请先登录.'
        })
        return false;
      }
      this.$axios({
        url: `${this.$settings.base_url}/order/pay/`,
        method: 'post',
        data: {
          'subject': course.name,
          'total_amount': course.price,
          'pay_type': 1,
          'courses': [course.id,],
        },
        headers: {'token': token},
      }).then(response => {
        console.log(response.data);
        if (response.data.code===0){
          open(response.data.data.pay_url, '_self');
        }
      }).catch(errors => {
        console.log(errors);
      })
    },
  }
}
</script>

<style scoped>
.course {
  background: #f6f6f6;
}

.course .main {
  width: 1100px;
  margin: 35px auto 0;
}

.course .condition {
  margin-bottom: 35px;
  padding: 25px 30px 25px 20px;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 2px 4px 0 #f0f0f0;
}

.course .cate-list {
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
  padding-bottom: 18px;
  margin-bottom: 17px;
}

.course .cate-list::after {
  content: "";
  display: block;
  clear: both;
}

.course .cate-list li {
  float: left;
  font-size: 16px;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
  border: 1px solid transparent; /* transparent 透明 */
}

.course .cate-list .title {
  color: #888;
  margin-left: 0;
  letter-spacing: .36px;
  padding: 0;
  line-height: 28px;
}

.course .cate-list .this {
  color: #ffc210;
  border: 1px solid #ffc210 !important;
  border-radius: 30px;
}

.course .ordering::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering ul {
  float: left;
}

.course .ordering ul::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering .condition-result {
  float: right;
  font-size: 14px;
  color: #9b9b9b;
  line-height: 28px;
}

.course .ordering ul li {
  float: left;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
}

.course .ordering .title {
  font-size: 16px;
  color: #888;
  letter-spacing: .36px;
  margin-left: 0;
  padding: 0;
  line-height: 28px;
}

.course .ordering .this {
  color: #ffc210;
}

.course .ordering .price {
  position: relative;
}

.course .ordering .price::before,
.course .ordering .price::after {
  cursor: pointer;
  content: "";
  display: block;
  width: 0px;
  height: 0px;
  border: 5px solid transparent;
  position: absolute;
  right: 0;
}

.course .ordering .price::before {
  border-bottom: 5px solid #aaa;
  margin-bottom: 2px;
  top: 2px;
}

.course .ordering .price::after {
  border-top: 5px solid #aaa;
  bottom: 2px;
}

.course .ordering .price_up::before {
  border-bottom-color: #ffc210;
}

.course .ordering .price_down::after {
  border-top-color: #ffc210;
}

.course .course-item:hover {
  box-shadow: 4px 6px 16px rgba(0, 0, 0, .5);
}

.course .course-item {
  width: 1100px;
  background: #fff;
  padding: 20px 30px 20px 20px;
  margin-bottom: 35px;
  border-radius: 2px;
  cursor: pointer;
  box-shadow: 2px 3px 16px rgba(0, 0, 0, .1);
  /* css3.0 过渡动画 hover 事件操作 */
  transition: all .2s ease;
}

.course .course-item::after {
  content: "";
  display: block;
  clear: both;
}

/* 顶级元素 父级元素  当前元素{} */
.course .course-item .course-image {
  float: left;
  width: 423px;
  height: 210px;
  margin-right: 30px;
}

.course .course-item .course-image img {
  max-width: 100%;
  max-height: 210px;
}

.course .course-item .course-info {
  float: left;
  width: 596px;
}

.course-item .course-info h3 a {
  font-size: 26px;
  color: #333;
  font-weight: normal;
  margin-bottom: 8px;
}

.course-item .course-info h3 span {
  font-size: 14px;
  color: #9b9b9b;
  float: right;
  margin-top: 14px;
}

.course-item .course-info h3 span img {
  width: 11px;
  height: auto;
  margin-right: 7px;
}

.course-item .course-info .teacher-info {
  font-size: 14px;
  color: #9b9b9b;
  margin-bottom: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
}

.course-item .course-info .teacher-info span {
  float: right;
}

.course-item .section-list::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .section-list li {
  float: left;
  width: 44%;
  font-size: 14px;
  color: #666;
  padding-left: 22px;
  /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
  background: url("@/assets/img/play-icon-gray.svg") no-repeat left 4px;
  margin-bottom: 15px;
}

.course-item .section-list li .section-title {
  /* 以下3句，文本内容过多，会自动隐藏，并显示省略符号 */
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
  display: inline-block;
  max-width: 200px;
}

.course-item .section-list li:hover {
  background-image: url("@/assets/img/play-icon-yellow.svg");
  color: #ffc210;
}

.course-item .section-list li .free {
  width: 34px;
  height: 20px;
  color: #fd7b4d;
  vertical-align: super;
  margin-left: 10px;
  border: 1px solid #fd7b4d;
  border-radius: 2px;
  text-align: center;
  font-size: 13px;
  white-space: nowrap;
}

.course-item .section-list li:hover .free {
  color: #ffc210;
  border-color: #ffc210;
}

.course-item {
  position: relative;
}

.course-item .pay-box {
  position: absolute;
  bottom: 20px;
  width: 600px;
}

.course-item .pay-box::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .pay-box .discount-type {
  padding: 6px 10px;
  font-size: 16px;
  color: #fff;
  text-align: center;
  margin-right: 8px;
  background: #fa6240;
  border: 1px solid #fa6240;
  border-radius: 10px 0 10px 0;
  float: left;
}

.course-item .pay-box .discount-price {
  font-size: 24px;
  color: #fa6240;
  float: left;
}

.course-item .pay-box .original-price {
  text-decoration: line-through;
  font-size: 14px;
  color: #9b9b9b;
  margin-left: 10px;
  float: left;
  margin-top: 10px;
}

.course-item .pay-box .buy-now {
  width: 120px;
  height: 38px;
  background: transparent;
  color: #fa6240;
  font-size: 16px;
  border: 1px solid #fd7b4d;
  border-radius: 3px;
  transition: all .2s ease-in-out;
  float: right;
  text-align: center;
  line-height: 38px;
  position: absolute;
  right: 0;
  bottom: 5px;
}

.course-item .pay-box .buy-now:hover {
  color: #fff;
  background: #ffc210;
  border: 1px solid #ffc210;
}

.course .course_pagination {
  margin-bottom: 60px;
  text-align: center;
}
</style>
